US 11,719,156 B2
Combined power generation system with feedwater fuel preheating arrangement
Byoung Gu Bak, Suwon (KR); Song Hun Cha, Osan (KR); Sung Gju Kang, Yongin (KR); and Hong Geun Ha, Yongin (KR)
Assigned to DOOSAN ENERBILITY CO., LTD., Changwon (KR)
Filed by DOOSAN ENERBILITY CO., LTD., Changwon-si (KR)
Filed on Feb. 22, 2022, as Appl. No. 17/677,006.
Claims priority of application No. 10-2021-0041385 (KR), filed on Mar. 30, 2021; application No. 10-2021-0041386 (KR), filed on Mar. 30, 2021; application No. 10-2021-0041387 (KR), filed on Mar. 30, 2021; and application No. 10-2021-0041388 (KR), filed on Mar. 30, 2021.
Prior Publication US 2022/0316395 A1, Oct. 6, 2022
Int. Cl. F02C 6/18 (2006.01); F02C 7/12 (2006.01); F02C 7/224 (2006.01); F02C 7/141 (2006.01); F01K 23/10 (2006.01)
CPC F02C 6/18 (2013.01) [F01K 23/10 (2013.01); F02C 7/12 (2013.01); F02C 7/141 (2013.01); F02C 7/224 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A combined power generation system comprising:
a gas turbine configured to combust fuel to generate a rotational force;
a heat recovery steam generator (HRSG) configured to heat feedwater using combustion gas discharged from the gas turbine and include a high-pressure section, a medium-pressure section, and a low-pressure section with different pressure levels;
a fuel preheater configured to heat fuel supplied to the gas turbine and include a primary heating part and a secondary heating part;
a high-pressure feedwater supply pipe connected to the high-pressure section to supply high-pressure feedwater to the fuel preheater;
a feedwater transfer pipe connecting the secondary heating part and the primary beating part to supply feedwater discharged from the secondary heating part to the primary beating part; and
a first feedwater control pipe connected to supply first medium-pressure feedwater to the feedwater transfer pipe, and
wherein the medium-pressure section includes a medium-pressure pump pressurizing and supplying the feedwater, a medium-pressure economizer receiving the feedwater from the medium-pressure pump and heating the received feedwater,
wherein the first feedwater control pipe is connected between the medium pressure pump and the medium-pressure economizer of the medium-pressure section,
wherein the high-pressure feedwater consists of liquid, and a phase of the high-pressure feedwater in the fuel preheater does not change and maintains a liquid state.